Apparatus for the separation of particles



Dec. 9, 1952 o. TEDMAN APPARATUS FOR THE SEPARATION OF PARTICLES Filed July 12, 1949 mw mm mm lll In filmin Davao 72' x k p/Vw. 3 Q2 9K Patented Dec. 9, 1952 OFFICE APPARATUS FOR THE SEPARATION OF PARTICLES Donald Tedman, South Kensington, London, England Application July 12, 1949, Serial No. 104,194 In Great Britain July 27, 1948 2 Claims.

This invention relates to the separation of particles and has for its main object to provide an improved apparatus for effecting the separation of minerals from their ores.

According to the invention the method consists in subjecting a suspension of particles to the action of controlling means whereby centrifugal forces are developed which cause the desired particles to be separated from the suspension and/or the other particles therein.

The invention also provides apparatus for effecting the separation of minerals or other particles which comprises a hollow container of substantially circular cross section tapering at each end to form oppositely disposed openings, the central circumferential part being of part tubular formation and having one or more tangential openings therein for the admission of a suspension of particles under pressure.

Preferably the central circumferential part of the container comprises a part tubular member disposed in the form of a helix which terminates at each end in part tubular members of substantially circular formation to which the tapering parts of the container are sealed in such a way as to form oppositely disposed annular depressions, each convolution of the helix being provided with an inlet tube tangentially disposed with respect to the helix.

The invention will be more completely understood from the following detailed description which is given in conjunction with the accompanying drawings, in which:

Figures 1 and 2 are end and side views respectively of an ore separating apparatus constructed in accordance with the invention: and

Figure 3 is a longitudinal cross-sectional view of the apparatus of Figs. 1 and 2.

In the ore separating apparatus shown in Figures 1 and 2 the container which is composed of glass or other mouldable material consists of a pair of coaxially disposed annular tubular parts I, 8 of substantially equal diameter, such parts having circumferential openings round their inner faces and being spaced apart by a tubular helix 9 which is connected at each end with the two annular tubular parts, and has a circumferential opening around the inner faces of its convolutions. The open-sided tubular helix thus delines a helical groove extending lengthwise of the container. To the exterior edges of the circumferential openings in the two spaced annular tubular parts there are sealed a pair of oppositely disposed funnel shaped members H), H having tubular openings i2, I3 through their remote ends in alignment with one another. These funnel 5 bered 16, n, 24 and 25.

shaped members may be of hyperbolic shape, their bases forming annular depressions l4, 15 with the walls of the annular tubular parts 1, 8 when they are sealed to the edges thereof. These funnel shaped members I9, ll thus provide two oppositely disposed tubular openings in the container which are coaxial with respect to the two annular tubular parts 7, 8 and the tubular helix 9. Into each convolution of the helix 9 an inlet tube l6, ll, 18, I9, 20, 2|, 22, 23 is sealed in such a way as to be tangentially disposed with respect to the circumference of the helix. Similar inlet tubes 24, 25 are sealed into the annular tubular parts I, 8 disposed at the opposite ends of the helix. All these inlet tubes are disposed in parallel planes substantially at right angles to the main axis of the container. In addition one of the convolutions of the helix, preferably the end one 24, may be provided with an additional inlet tube 21 as shown, this tube also being tangentially disposed with respect to the circumference of the helix. If desired a collector tube 26 may be arranged in the next convolution opposite the inlet tube 16 as shown.

Each of the aforesaid inlet tubes is provided with a slight constriction 28, so that the tube converges slightly just before it enters the helix so that when a stream of water and ore is delivered through any one of these tubes, a strong clean jet is formed as it passes from the inlet tube into the interior of the helix.

In affecting the separation of mineral such as for example lead sulphide from its ores, the ore is first sifted to form particles of a predetermined size range or mesh range and the resulting ore is mixed with water and forced under pressure into the container through one or more of the aforesaid inlet tubes, the container being preferably arranged with the axis in a horizontal plane. Conveniently, a few of the tubes at or near the central part of the helix are selected for this purpose, and plain water is forced through the re maining tubes, the pressure of water delivered to the tubes increasing successively from one end of the container to the other so that the water delivered through the tubes at one end has a very low pressure, while the water delivered through the tubes at the opposite end has a very high pressure, the pressure of water in which the ore is suspended being intermediate these two extreme pressures.

Alternatively, water containing the ore to be separated is forced into the container through the tubes numbered 22 and 23, whil plain water is forced at high pressure through the tubes num- This is usually found to' 3 be sufficient in the case of particles of moderate size, but where the particles are very small, Water at high pressure may also be forced through the remaining inlet tubes numbered l8, I9, 20, 2!.

With this arrangement, the suspension of ore on entering the container is Whirled round the interior walls of the central convolutions of the helix so as to set up a vortex in which centrifugal forces are developed. These forces cause the particles of the desired mineral to move towards the periphery of the container where they are temporarily retained within the walls of the helix. The remainder of the ore being lighter in weight escapes from the convolutions of the helix and is carried towards one end of the container by the. transverse current developed due to the varying pressure in the helical convolutions and is thus expelled from the funnel shaped part ii at that end of the container. Meanwhile the particles of the desired mineral are carried along the helix by the stream of water and as they approach the high pressure end they are themselves carried out by the transverse current. Due to the pressure falling to zero at each end of the container the transverse currents developed at each end will bein opposite directions and the process of separation will thus be continuous, the particles of mineral being carried out at one end and the lighter particles, such as sand, in suspension will be carried out at the other end I I. The amount of the heavier constituent of the ore proceeding along the helix to the higher pressure end and therefore the degree of separation can be controlled by adjusting the pressures of the Water inlets in the higher pressure half of the helix, or if the ore and water are forced through inlet tubes 22 and 23 by varying the high pressure inlets l6, I1, 24. and 25.

In cases where a collector tube 26 is employed, the particles of; mineral on reaching the end of the helix are carried out through the collector tube, while the lighter particles in suspension such as quartz sand will be carried out through the tubular opening 13 at one end, the remaining water emerging through the opposite end l2.

It will be understood, however, that the invention is not to be regarded as being in any way limited to the particular construction of apparatus hereinbefore described since it is obvious that it is capable of a variety of modifications; for example while I prefer to provide the helix with convolutions this number may be varied according to requirements. While I prefer to provide one inlet tube to each convolution, additional tubes, such as 27, may be provided if desired. The annular tubular members 7, 8 at each end may also be provided with additional tubes forthe purpose of varying the internal pressure set up. Furthermore, while I prefer to introduce the ore as a suspension in water any other suitable liquid may be employed or the ore might be forced into the container as a dry powder in an air stream.

It is also to be understood that While the invention is mainly applicable to the separation of minerals from their ores, it may also be employed for sorting a mixture of particles into groups of different sizes, the apparatus being used as a particl classifier or sizer.

The aforesaid container may be constructed in a variety of different sizes according to the nature of the ore for which it is to be used. A suitable container for extracting lead sulphide particles of diameters ranging from inch to 4 inch is one in which the overall diameter of the annular tubular part 9 is approximately 2 inches, the product of this diameter and the thickness of the tubular part being approximately 0.6 sq. in.

It is to be understood that while the invention is mainly intended for extracting minerals from their ores, it may also be employed for separating particles of different substances from one another when such substances possess different values of specific gravity.

It will thus be seen that the invention may also be employed for de-sliming an ore, the apparatus beingused to eliminate the very small particles which are liable to interfere with chemical separators, thus obviating the use of screens and like devices.

In addition to the above, the invention may also be employed to reduce the water/solid ratio in a suspension of solids in water. For example if fine sands are to be treated but are contained in suspension in water the ratio of Water to sand by weight say being 10/1, this bulk of water may be reduced to a ratio of say 1 of water to 2 of solids by passing th suspension through the separator, as hereinbefore described.

I claim:

1. An apparatus for separating particles of different specific gravities or sizes comprising a stationary, hollow, circumferentially closed container having a wall of substantially circular internal cross-section, unobstructed tapered fluid-discharge outlets at opposite ends of the container, the Wall of said container being internally formed to provide a continuous, uninterrupted helical groove extending lengthwise between the ends of the container and providing a plurality of complete turns for the migration of separated material along the groove to an end of the container, and a plurality of fluid inlet openings in the wall of the container located at spaced distances along the container intermediate its ends, said inlet openings being disposed tangentially of the helical groove and of approximately the, width of the helical groove for discharging fluid into the helical groove.

2. An apparatus for separating particles as set forth in claim 1, including tubes individually associated with the inlet openings for delivering fluid to the helical groove, each tube having a constricted portion adjacent its discharge end to produce a jet discharge of the fluid.

DONALD TEDMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 468,935 Morse Feb. 16, 1892 696,606 Stebbins Apr. 1, 1902 762,867 Allen June 21, 1904 825,807 Clarke July 10, 1906 958,942 Seymour May 24, 1910 1,505,741 Stebbins Aug. 19, 1924 2,102,525 Freeman Dec. 14, 1937 2,175,563 Green et a1 Oct. 10, 1939 2,273,271 Kerns Feb. 17, 1942 2,301,371 Corwin Nov. 10, 1942 FOREIGN PATENTS Number- Country Date Great Britain Jan. 2, 1885 

